I both liked it and hated it at the same time. Every episode I was watching nervously, expecting it to disapoint me. Sometimes it did, sometimes they did better than I could have wished for. I've watched the Thai version and have a strong opinion about it, so I was excited to see what the Japanese director had taken out of it and how she had decided to adapt it. I have a lot to criticize in both shows, so for my own satisfaction, I'm going to compare them point by point before I express my general feelings about Koi no Yokan.

STORY
Win: Thailand
The Japanese version follows pretty much the original story but of course, as it has less episodes, they had to cut and compromise some stuff. I liked the way they did it overall but there are two things that bothered me; First, merging Arashi's and Rei's two NC scenes into one. In the original, I didn't really care about their first time, but the scene after Payu won the race was amazing because it showed really how they had grown to care more about each other than anything else, and how well they worked together. It was so important for their chemistry developpement. Merging it and making that scene their first time in KNY takes away that developpement and makes the moment way less powerful. Also, they decided to have Rei tell Arashi about his assignment after the race, which made it look like he didn't care that much about Arashi's achievement. I was really fond of the way Rain was super supportive and proud of him in the original, and by merging these two moments they completly lost that aspect of their couple. Second thing, having both Kai and Rei's assault in the same episode made it more difficult to empathize with them individually.

RYTHM
Win: Japan
As much as the cuts mentionned above upsetted me, it was soooooo much easier to watch than the original. Like in many Thai dramas, LITA tends to include many elements/scenes that are just slow and do not bring much to the story. KNY was efficient, straight to the point but didn't feel rushed, at least to me.

PHOTOGRAPHY
Win: Thailand
Not that LITA was specifically well filmed, but still, once again, it's about the chemistry and proximity. KNY had way fewer, longer and more distant shots. Some scenes were almost filmed entirely in one shot. It's a style I usually enjoy very much, but in this case it kind of made it look like a theatre play. It kept me distant from what was happening on the sceen, like I was watching from afar all the time. So of course it was harder to feel that proximity between the characters, but it also reduced the impact of the action scenes. I liked the colorimetry though, it was very lively.

SOUND
Win: Japan
I didn't notice much about the music in both shows. But the sound in LITA was just horrible, and in KNY it was... well... done by professionnals who have been paid correctly, probably. One moment where the music did hit me was the scene in the car where Arashi is all over Rei. In LITA, in the bathroom stall, it's an angsty music which really adds to the assault Payu is doing and made me highly uncomfortable. In KNY, it's more of a sensual, slow music that eases it up and contribute to making it look less aggressive, so good point.

CHARACTERS
I'm not going to talk about the acting, because I believe everything the actors did was a choice made on purpose by the director, and therefore is a part of the characters and not the actors' capacities. For example, everyone criticized Rei's actor for not being able to do a proper kiss in their NC scene, but he showed us in the last episode that he was well capable of kissing, which means that it was the director who had decided he would act like that in the first scene. SO, here goes what I think of the characters:
REI: Thailand wins
I didn't really like Rain in the first place but Rei was.... insufferable. His infinite baby talk, the way he moved, his actions.... He was more stupid, more selfish and had pretty much nothing interesting to offer.
ARASHI: Thailand wins
In LITA, I hated Payu at first and grew to like him after they got together. I despised him for harassing Rain sexually, but then I liked how he became much more soft, cool but still sensitive to what happened to him and his boyfriend, and overall very expressive. One good thing about Arashi is that he wasn't as agressive with the whole sexual assault, just a bit pushy, but otherwise he was just plain boring. Just that cool guy who is too cool to show any emotion. Even when Rei got kidnapped he gave us nothing, just a semi angry swing and slightly anxious eyes when he got to Rei being tied up on the chair.
KAI: Tie
I really liked both. Maybe I was a bit disapointed when Kai wasn't as sassy as Sky, but still I think his character made sense and I was very fond of the more taciturn aspect.
FUMA: Japan wins
Yeah, Prapai was amazing after they got together. But christ how painful it was to watch him harrass the sh*t out of Sky in the beginning, so much that Sky actually had somewhat of a panic attack at some point. Fuma was just as sweet, just as much of a green flag, but without the aggressive harrassment. Like Arashi, he is a bit pushy and doesn't give up but it is very light. Even the first time they met at the race, unlike Prapai, Fuma doesn't actually pressures Kai into sleeping with him, as he says he's kidding after asking him for "something in return" (though it doesn't make much sense why Kai actually sleeps with him then but still, it makes Fuma way more likable).

CHEMISTRY
Win: Thailand, of course
BUT ! Like I already mentionned, people criticized the intimate scenes in KNY a lot because it was awkward and everything, condemning it as if the director had no clue what she was doing or whatever. I did at first too. But after watching Kai and Fuma's second NC scene and Arashi and Rei's bath scene, I realized it was probably more deeply thought by the Director. I don't know since I'm not in her head, but I feel like she purposely made it awkward for Arashi and Rei since it was their first time, and as much as I hated that scene, I think it contributed to the satisfaction of the bath scene. Same for Fuma and Kai, she probably made their first time awkward since Kai was forcing himself and Fuma didn't think much of him at that time, and it deepened the gap between that and their second time which was very sweet and much more smooth. So, I actually didn't hate their chemistry in KNY. Because of their individual characters, I'm kinda still wondering why are Rei and Arashi together, but Kai and Fuma had, in their own way, just as much chemistry as the Thai couple.

In Conclusion, as I didn't particularly love the original story, I didn't expect to be much fond of this one either. But overall Koi No Yokan was a nice, easy watch and is even more enjoyable if you're used to the Japanese style. Though Fuma and Kai's story only is 80% of the reason why I liked it, I'll keep a good memory of the whole show and wouldn't mind watching it again.

Despite everything above, I do not think an adaptation has look like the original or even do it justice. I just compared them because I watched them both, but Koi no Yokan stands well by itself and I'm sure the people who haven't seen LITA don't think as bad of this show as the people who did. Would recommend to the people who are used to Japanese shows and those who can look over Rei's despicable character lol.